Natural Recovery and Impaction of Landslide and Debris Flow within Habitat of Yunnan Snub-nosed Monkeys in Baimaxueshan Nature Reserve

Landslide and debris flows, a serious geological disaster, are common at the edge of the Tibetan Plateau, and damage the surface vegetation. Like other natural disasters, landslide and debris flows cause a shift in local ecological conditions, which can have profound impacts on the habitat of non-human primates. This study investigated the characteristics of surface vegetation found within the debris field of a landslide and debris flow that occurred in 2008 at Gehuaqing in Baimaxueshan Nature Reserve ten years later. We calculated the surface area of the debris field to be 71672.96 m(2), affecting around 312500 m2 of the known home range of a resident Yunnan snub-nosed monkey group. A field survey was conducted to sample the vegetation within the area of the landslide and debris flow after it had been allowed to grow for ten years. In total, 27 plant species were observed within the debris field, all classified as either shrubs or herbaceous plants. Gnaphalium hypoleucum had the highest importance value of the herbs (27.48%), while Leycesteria formosa had the highest importance value of the shrubs (17.33%). The Shannon-Wiener diversity index was significantly higher in the lower section and the Bray-Curtis distance was significantly lower, suggesting vegetation recovery has progressed faster on the lower end of the debris field. The speed of restoration within the landslide and debris flow area is important for the protection of Yunnan snub-nosed monkeys living at Gehuaqing. A reasonable plan for vegetation restoration according to the composition of the surrounding community could mitigate population reductions in the monkeys and other local wildlife.